The present invention relates to medical products which are worn on the skin and fastened by an overplaster. These products may be transdermal therapeutic systems (TTS) which, besides the part containing active ingredient, additionally an active-ingredient-free overplaster, which has a specific construction, but also diagnostic agents or cannulas which are fixed by a piaster dressing. As is known, TTS are medicinal products in patch form which are adhered to the skin and are required to deliver at least one active ingredient over the entire administration time. It is obvious that, these medical properties must adhere well, since otherwise there can be no delivery of active ingredient to the skin, the diagnostic agent does not work reliably, or the cannula slips. At the same time, instances of skin irritation must be prevented, meaning that the inherent tack of the TTS, diagnostic agent or cannula fixing plaster may not be higher than is absolutely necessary.
Adhesive bonding, as is known, refers to the joining of two surfaces by an adhesive that connects the surfaces to one another through adhesion and cohesion. The adhesive here has to wet the respective surfaces. It follows from this that effective tack is governed not only by the adhesive but also by the nature of the surfaces. But different people, particularly with progressing age, have skins with different surfaces, with the individual skin types varying in their sensitivity of reaction to skin irritations. Although this requirement is familiar to the art, there are still no medical products which address this issue.
EP 1 992 363 discloses a transdermal patch having a backing laver and a pressure-sensitively adhering layer, which in turn comprises an active ingredient reservoir layer and a layer which adheres on the skin. The active ingredient reservoir layer comprises a pressure-sensitive acrylate adhesive, while the layer that adheres to the skin comprises a styrene-isoprene-styrene block copolymer.
DE 10 2004 038 285 A1 discloses a patch system for the release of essential oils via the ambient air or transdermally without irritation to the mucosae or the skin. The patch system comprises a polymer matrix in which at least one essential oil is homogeneously distributed, a support layer, and a removable protective layer. Additionally, there may be a blockage layer impermeable to essential oils, a permeation-controlling membrane or a pressure-sensitive adhesive layer present.
Subject-matter of DE 10 2006 054 731 A1 is a transdermal therapeutic system for administering, buprenorphine. This system comprises a backing layer impermeable for the active ingredient, a matrix layer based upon polysiloxane or polyisobutylene, and comprising as well as buprenorphine at least one carboxylic acid, and a detachable protective layer.
Disclosed in EP 2 759 294 A1 is a patch for the transdermal administration of fentanyl or a fentanyl homolog. The patch comprises a backing layer, a barrier layer, a pressure-sensitively adhering active ingredient layer, and a removable protective layer (release layer). The active-ingredient-containing layer contains fentanyl or a fentanyl homolog, an agent for improving the permeation of the fentanyl or the fentanyl homolog, and an acrylate adhesive. The acrylate adhesive is either a nonfunctional polyacrylate adhesive or a polyacrylate adhesive which contains carboxyl groups.
Plasters of polyacrylates which can be utilized over a wear time of up to at least 7 days, are known from US 2009/0130190 A1, for example. Particularly when worn for a long time, plasters of this kind load generally, on redetachment, to significant pain for the skin affected, and to increased visible residues on the skin. A further factor is the commonplace use of basis weights of more than 80 g/m2, with the disadvantage of higher residual monomer contents in the plaster as a whole. The origin of this is that for overplasters, which are designed for at least 7 days, it is common for acidic polyacryate adhesives (monomers have free acid functions) to be used, without additions such as neutral oils, and they therefore enter into a very strong bond to the skin.
In the case of silicone adhesives containing active ingredient, amine-resistant silicone adhesives are often utilized as skin contact layers. These adhesives often have the disadvantage that on account of their amine resistance, they exhibit relatively low bonding to the skin, since all of the terminal silanol groups are capped by methyl groups. With the commonplace silicone adhesives, therefore, it is often very difficult to attain a wear time of at least 7 days or more. Additionally, amine-resistant polysiloxane adhesives have lower water vapor transmissibility figures than is the case for non-amine-resistant versions of the polysiloxane adhesives, and so the occlusion effect is smaller with these adhesives. This disadvantage can be compensated if utilizing an overplaster which adheres with high compatibility to the skin for at least 7 days. As a further aspect, a single-sided siliconized film (e.g. 19 or 23 μm PET film with single-side siliconization) is often utilized as a backing layer in the case of silicone piasters containing active ingredient. Here, the deleterious effect occurs that it also has silicone residues on the nonsiliconized side, since the rolls are wound into themselves, causing the nonsiliconized side to make contact with the siliconized side. The adhesion relative to the active-ingredient-containing silicone adhesive layer is therefore good, but is lower than that of an overplaster based on acrylate adhesives. Consequently there may be instances of premature detachment (and/or poor adhesion) between overplaster and active ingredient-containing matrix with a release layer composed of single-sidedly siliconized film (or backing layer). This disadvantage can be compensated by an active-ingredient-free overplaster which is based on non-amine-resistant silicone adhesives.